1. Field of the Invention
The present invention is related to the field of bottle handling apparatus, and more particularly to apparatus for removing bottles from a full depth case and delivering the bottles to a conveyor.
2. Prior Art
Bottle cases, as commonly used for soft drinks and the like, are generally characterized as one of two kinds. The first type of case is referred to as the half depth case, and is characterized by a depth which is only a fraction of the height of the bottles intended to be used in the case. Such cases generally provide for bottle separation and have handles on the ends thereof for lifting, but only extend part way up the bottles and support the lower part of each bottle in the sidewise direction. Thus, in stacking such cases, each case is stacked upon the tops of the bottles on a lower case. In terms of removing bottles from such half depth cases, the neck portion of each of the bottles is available without having to reach over the edge of the case, so that apparatus may be disposed to intercept and grasp the necks of the bottles as the cases pass thereunder. One such type of half depth uncaser is disclosed in U.S. Pat. No. 3,570,693 by John J. Peyton, issued Mar. 16, 1971 and assigned to Industrial Automation Corporation, Santa Barbara, California, the assignee of the present invention.
The second type of bottle case is characterized as having a depth substantially equal to, but generally slightly greater than the height of the bottles to be used therein, so that upon stacking, each case rests upon the top of the lower case, rather than upon the tops of the bottles. To unload bottles from such cases, apparatus must be provided for effectively reaching into the case to grasp the bottles and lift them therefrom. Thus, such apparatus may not be disposed so as to merely intercept the necks of the bottles, as the cases pass the apparatus, but instead some form of bottle gripper must be inserted over the edges of the cases to grasp each bottle therein, thereby requiring synchronization in the position and operation of the grippers with respect to the motion or position of cases within the case unloader.
There are two types of full depth uncaser grippers which are commonly used. The first type of gripper is characterized as having a substantially rigid outer cup-like structure, with the open portion directed downward so as to be disposable over the tops of the bottles. Within the top is a generally angular, flexible (usually rubber) inner wall sealed with respect to the top so that the region between the flexible inner wall and the cup may be pressurized to encourage the inner wall to a smaller diameter to close around the neck of a bottle. Thus, when the gripper is placed down near the neck of a bottle, there is clearance between the neck and the flexible inner wall. However, upon pressurization of the gripper, the inner wall moves inward to grasp the neck of the bottle and retain the bottle with respect thereto. Characteristically, this type of gripper is supported in a downward projecting direction by a rubber member supported by some form of continuous belt or chain system coordinated with respect to the motion of cases thereunder to reach into the cases, grasp bottles, lift them free of the case and deliver them to a delivery station.
The grippers described above operate well under most conditions. However, they have certain characteristics which cause occasional problems, and are subject to deterioration and puncture so as to require occasional replacement. By way of example, if a bottle in a case has a broken neck, the sharp edges may cut and puncture a gripper. Similarly, excessive pressure sometimes presented in an effort to increase the speed of operation of the device may result in deterioration and blow out of a gripper, particularly if the equipment is operated without bottles passing therethrough. Also, the screw cap bottles, also referred to as convenience closure bottles, as often returned with the caps thereon (as specifically requested) or at least loosely disposed over the tops of the bottles. Thus, the gripper may grip such a cap and remove it from the bottle but not release the cap at the position where the bottle should have been released, so that the cap remains in the gripper to jam the gripper from further operation. Also, if a bottle in a case is tilted or upside down, that bottle may force the corresponding gripper to the side so as to interfere with the proper disposition of surrounding grippers, thereby resulting in as much as one-half of the case or more not being unloaded as a result of the problem with merely one bottle in the case. Obviously, this equipment requires a substantial supply of compressed air, as well as expensive valving, plumbing, etc. to couple the air supply to the individual grippers and to coordinate the action of individual grippers.
The second type of full depth uncaser utilizes a purely mechanical gripper having a pair of gripping fingers spring-loaded to the closed position, but encouragable to the open position by the engagement of an actuating member with a cam surface as the grippers move along their predetermined track determined by a continuous chain system. These grippers are characterized as requiring considerable motion of the grippers along their predetermined paths of travel for the gripper to either open or close, since a significant length of cam engagement is required to force the gripper to the open position, or conversely to allow the gripper to smoothly return to the closed position. Consequently, such gripper follow a predetermined path characterized by motion having a substantial downward component to project the gripper into a case while the gripper is in the open condition, followed by a substantially horizontal motion during which time the gripper is allowed to close, then followed by motion having a substantial upward component to lift the bottle out of the case. Since all grippers are supported on a continuous chain arrangement, the horizontal component of velocity of the grippers during these three segments of the chain path cannot be equal, whereas the horizontal velocity of the cases under the grippers is uniform. Thus, such grippers are characterized as having some elongated characteristic in a longitudinal direction so as to allow some longitudinal motion of the bottles with respect to the grippers. Since the grippers must be accurately inserted into the case, the net result is that the grippers, and particularly the bottles, tend to drag against the edge of the cases when being lifted therefrom, resulting in substantial swinging of the bottles once free of the case. Also, such gripper tend to be mechanically complex, and close to a fixed position so as to grasp the bottles with varying degrees of security depending upon the exact size of the neck of the bottles. In this regard, the grippers are purposely fabricated so as to not firmly grasp the bottles, since some longitudinal sliding of the bottles in the elongated grippers is desired to accommodate the variations in the horizontal component of velocity of the grippers with respect to the cases.